Presently, mobile handsets utilize a variety of technologies and formats which may include, for example, GSM (Global System for Mobile Communication), CDMA (Code Division Multiple Access) and/or UMTS (Universal Mobile Telecommunications System) technology depending on the carrier of choice. Network provisioning data necessary to access cellular networks using GSM and UMTS technologies are stored on a Subscriber Identity Module (SIM), commonly known as a SIM card, which are plugged into mobile devices. Analogous devices for other mobile network systems have been developed, such as Removable User Identity Module (RUIM), Universal Subscriber Identity Module (USIM) or Universal Integrated Circuit Card (UICC). Collectively, these smart card devices are often referred to as smart cards or SIM cards.
The SIM card is a detachable memory module containing the user's cell phone provisioning or subscription information as well as personal data, such as phonebooks, saved SMS messages, downloaded data, etc. By storing such information on a SIM card, mobile device users can replace their mobile devices while keeping the same service provider subscription and retaining their personal data information simply by removing the SIM card from the old device and plugging it into the new one.